Does anyone know if SS1 did the full burn time of 88 seconds on the X2 flight - it didn't feel like it to me.

I know the burn went on for longer than the X1 flight as the height reached was 30,000 or so feet higher, but I was wondering how much more kick the SS1 had, and if they turned it off early, why they did so? (another envelope expansion flight again?)

dunno if they shut it down early again, but if they did, it was the prudent thing to do. Higher you go, faster you go coming down, subjecting the ship to higher loads and increasing the risk of something breaking off or jamming.

Each of the last three SpaceShipOne flights has had the goal of breaking the X-15 altitude record of 67 miles. This last one was the first one where they didn't lose altitude to one condition or another.

No Franklin, I think you are wrong about the intent of Rutan's barnstormers. I was pretty sure the goal had something to do with winning some sort of prize. I note that you managed to once again squeeze in a reference to the X-15, your most favorite thing, many points for achieving a somewhat difficult manouevre there. In any case it doesn't even approach answering dolby_uk's question.

Actually, I don't know the answer either, but I figure if Franklin can burn bandwidth pointlessly then I can too . However, I will at least throw in a supposition or two.

If they didn't do the full burn time (hopefully we'll learn about the details soon) then it's probable that the pilot made sure that the burn was long enough to include a reasonable margin for success.

Isn't that the maximum burn-time though? Maybe they did the maximum? I'm just interested in how much lea-way they had - the further up you go, the more zero-g, which for paying passengers is more worth the money. Mind you, it also implies greater g-force on you on the way down I believe.

Btw DKH, I would think that breaking the X-15 altitude was in Rutan et al's minds, although not the primary objective obviously

September 29, 2004: At 8:13 this morning PDT, SpaceShipOne (SS1) coasted above the 100 km altitude point and successfully completed the first of two X-Prize flights. The peak altitude reached was 337,500 ft. The motor was shut down when the pilot, Mike Melvill, noted that his altitude predictor exceeded the required 100 km mark. The motor burn lasted 77 seconds – 1 second longer than on the June 21st flight. Melvill was prepared to burn the motor up to 89 seconds, which indicates significant additional performance remains in SS1.

Using the extremely scientific method of watching time tick off on my video of X2 , burn time was 85 +/- 1 seconds. I've been to all three space flights and this is the first time I got the entire burn on tape - it was SO cool!